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For Educators · Moment of Inertia

Moment of Inertia for a spinning top

Built for educators teaching it to a class. Drop a live demo into a lecture or assign it as a shareable link — no lab installs. Simulate a spinning top live below — adjust the inputs and watch it respond, right in your browser.

Moment of InertiaLive

rotational mass & the parallel-axis theorem

Controls

Shape

Presets

Mass (kg)

Size R or L (m)

Axis offset d (m)

Moment of inertia is rotational mass: how hard it is to spin an object. Mass farther from the axis counts more (∝ r²). The parallel-axis theorem adds md² when the axis moves off the center of mass.

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Data Inspector

I about center0.0900 kg·m²

Parallel-axis term0.0000 kg·m²

Total I0.0900 kg·m²

Governing equation

I = 0.500 M R^{2} + M d^{2} = 0.0900 + 0.0000 = 0.0900 kg \cdot m^{2}

Reading this result: The axis runs through the center of mass, so there is no parallel-axis penalty — this is the smallest moment of inertia this body can have.

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Frequently asked questions

Is this good for educators?: Yes — this version of "Moment of Inertia for a spinning top" is framed for educators teaching it to a class. Drop a live demo into a lecture or assign it as a shareable link — no lab installs.
Do I need to install anything?: No. It runs in any modern browser, free, with no account required.